One problem which is commonly encountered by disabled persons who must rely on wheelchairs for their mobility is that conventional wheelchairs are relatively wide and cannot conveniently pass through many openings or passageways. Thus, the doors on some bathrooms, the aisles in airplanes and theaters, and other halls and doorways can present a barrier which will restrict passage by those who must depend upon wheelchairs for their mobility.
Little has been done to overcome this problem. While there are numerous devices which are designed for attachment to and in some cases carrying by a wheelchair to enable standing or walking by the wheelchair user, these apparatus incorporate the chair as part of the overall walker assembly. Thus, such walker assemblies have width dimensions which are at least as great as the wheelchair, and sometimes greater. Examples of U.S. Patents directed to such wheelchair walkers are U.S. Pat. Nos. 3,999,778, 3,719,390, 3,584,890, 3,405,954, 3,398,974 and 2,596,055.
At least one attempt has been made to provide a wheelchair which is adaptable for movement through relatively narrow passageways. Such apparatus is disclosed in U.S. Pat. No. 4,098,521. This patent discloses a wheelchair which can be converted to a narrow attendant-propelled wheelchair by removal of the main drive wheels. While this may be an acceptable approach for many applications, it has disadvantages that limit its usefulness.